This invention relates generally to communications systems and, in particular, to satellite communications systems wherein a plurality of user terminals are in bi-directional wireless communication with a terrestrial communications network via a gateway and at least one satellite.
In conventional terrestrial cellular communication systems it is often the case that a user is billed at a predetermined rate on a per minute basis for the use of the system. However, in a satellite-based communication system this type of billing arrangement may not accurately reflect a correct billing amount. By example, a user who is uploading or downloading a large data file though a satellite at 9.6 kb/s will most likely consume more of the system resources (e.g., satellite power) than another user who is engaged in a voice communication at an average speech bit rate of less than 4 kb/sec. The result is that an inequitable billing arrangement may exist, whereby some users effectively subsidize the usage of the system by other users.
The above-referenced U.S. Pat. No. 5,664,006 and the continuation application thereof teach the monitoring of various parameters of the communication link(s), for example, the amount of system power and/or bandwidth that is used, to derive an amount to bill for a connection. Also taught is the accumulation of system usage data and the outputting of the data to a central site for use in billing a service provider.
While these disclosed techniques are very well suited for use in connection-oriented communications, such as circuit-switched voice connections, the inventors have realized that for so called xe2x80x9cconnectionlessxe2x80x9d communications, such as those found in packet-based communication sessions typified by those employing the Internet Protocol (IP), a different type of system usage accounting may be more desirable.
In a typical circuit switched system a particular circuit is assigned to and xe2x80x9cowned byxe2x80x9d a particular user until the connection is terminated (e.g., the user goes on-hook to end or release a voice call). In this case the connection may be thought of as a xe2x80x9ctubexe2x80x9d, where information such as digitized voice or data is put in one end of the tube and then extracted at the other end of the tube. However, in a typical connectionless system each message (e.g., data packet or datagram) carries a full or partial address of a destination for the message, and each message can be routed through the data communications network and system independently of all other messages. It is possible in this case that a first datagram sent at time T1 can arrive later than a second datagram sent at a later time T2, depending on the routing particulars for each of the datagrams. In a connection-oriented system this type of operation is impossible.
It is a first object and advantage of this invention to provide an improved method and apparatus for accounting for system usage in a connectionless type of satellite communication system.
It is another object and advantage of this invention to provide an improved method and apparatus for accounting for session-based system usage in a satellite communication system wherein users employ IP or other types of protocols.
It is a further object and advantage of this invention to provide an improved method and apparatus for aggregating system usage data for billing system service providers.
The foregoing and other problems are overcome and the objects and advantages of the invention are realized by a method and apparatus for accurately accounting for an amount of satellite communications system resources that are utilized for connectionless data communication links.
In accordance with the teachings herein an embodiment of a method is disclosed for operating a satellite communications system. The method includes the steps of (a) establishing a session with a user terminal using a gateway that is coupled to the user terminal through at least one satellite via an inbound link and an outbound link, where the gateway is further coupled to a data communications network; (b) during the connection, determining at the gateway a number of units of data transfer, such as bytes, that are used during the session on at least one of the inbound link and the outbound link; and (c) determining an amount to bill for the session based at least in part on the determined number of units of data transfer. The step of determining an amount to bill may also be based on a number of user terminals that simultaneously share a communication channel that carries at least one of said inbound link or said outbound link. The step of determining an amount to bill is preferably executed at a mobile satellite system operator site based on aggregated user billing information received from the gateway. The step of determining an amount to bill may also be executed at the gateway.
More particularly, disclosed herein is a method for operating a satellite communications system for coupling a user terminal to a data communications network. A satellite communications system that operates in accordance with the method is also envisioned. The method has steps of (a) establishing a connectionless packet data transmission link between the user terminal and a gateway that is coupled to the user terminal through at least one satellite via an inbound link and an outbound link, the gateway being further coupled to the data communications network and being associated with a gateway service provider; (b) deriving billing-related information by counting a number of units of data that comprise data packets that are transmitted over at least one of the inbound link and the outbound link; (c) aggregating the billing-related information with billing-related information for other user terminals; (d) transferring the aggregated billing-related information to a satellite communication system operator site; and (e) at the satellite communication system operator site, determining an amount to bill the gateway service provider based at least in part on the aggregated billing-related information. The step of establishing the connectionless packet data transmission link may include a step of varying a bandwidth of the link to accommodate different data rate requirements. The data packets are preferably transferred to and from a host computer in
accordance with an Internet Protocol (IP). Further in accordance with embodiments of this invention the service provider billing can be based on a (bandwidth*time) product that is used on at least one of the inbound link and the outbound link or, during the session, by determining a number of units of content that are transferred at least from the gateway to the user terminal. Units of content may be, by example, downloaded pages and/or requested for specific units of content, such as stock market quotations.
In accordance with a further example of this invention a method allocates satellite system resources to a satellite system service provider based at least in part on a predicted demand for the satellite system resources for the satellite system service provider and, during a time that the satellite system resources are allocated to the satellite system service provider, executes further steps of recording an actual demand for the satellite system resources; comparing the actual demand to the predicted demand to determine a difference between the actual demand and the predicted demand; and then billing the satellite system provider an amount that is a function of the determined difference between the actual demand and the predicted demand.